ORCID Profile
0000-0001-8862-4042
Current Organisation
Universidade Federal da Paraíba
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Publisher: Cold Spring Harbor Laboratory
Date: 25-03-2021
DOI: 10.1101/2021.03.25.436973
Abstract: Evolutionary studies require solid phylogenetic frameworks, but increased volumes of phylogenomic data have revealed incongruent topologies among gene trees in many organisms both between and within genomes. Some of these incongruences indicate polytomies that may remain impossible to resolve. Here we investigate the degree of gene-tree discordance in Solanum, one of the largest flowering plant genera that includes the cultivated potato, tomato, and eggplant, as well as 24 minor crop plants. A densely s led species-level phylogeny of Solanum is built using unpublished and publicly available Sanger sequences comprising 60% of all accepted species (742 spp.) and nine regions (ITS, waxy , and seven plastid markers). The robustness of this topology is tested by examining a full plastome dataset with 140 species and a nuclear target-capture dataset with 39 species of Solanum (Angiosperms353 probe set). While the taxonomic framework of Solanum remained stable, gene tree conflicts and discordance between phylogenetic trees generated from the target-capture and plastome datasets were observed. The latter correspond to regions with short internodal branches, and network analysis and polytomy tests suggest the backbone is composed of three polytomies found at different evolutionary depths. The strongest area of discordance, near the crown node of Solanum, could potentially represent a hard polytomy. We argue that incomplete lineage sorting due to rapid ersification is the most likely cause for these polytomies, and that embracing the uncertainty that underlies them is crucial to understand the evolution of large and rapidly radiating lineages.
Publisher: FapUNIFESP (SciELO)
Date: 2021
Publisher: Springer Science and Business Media LLC
Date: 26-04-2023
DOI: 10.1038/S41586-023-05971-3
Abstract: Tropical forests face increasing climate risk 1,2 , yet our ability to predict their response to climate change is limited by poor understanding of their resistance to water stress. Although xylem embolism resistance thresholds (for ex le, $$\\varPsi $$ Ψ 50 ) and hydraulic safety margins (for ex le, HSM 50 ) are important predictors of drought-induced mortality risk 3–5 , little is known about how these vary across Earth’s largest tropical forest. Here, we present a pan-Amazon, fully standardized hydraulic traits dataset and use it to assess regional variation in drought sensitivity and hydraulic trait ability to predict species distributions and long-term forest biomass accumulation. Parameters $$\\varPsi $$ Ψ 50 and HSM 50 vary markedly across the Amazon and are related to average long-term rainfall characteristics. Both $$\\varPsi $$ Ψ 50 and HSM 50 influence the biogeographical distribution of Amazon tree species. However, HSM 50 was the only significant predictor of observed decadal-scale changes in forest biomass. Old-growth forests with wide HSM 50 are gaining more biomass than are low HSM 50 forests. We propose that this may be associated with a growth–mortality trade-off whereby trees in forests consisting of fast-growing species take greater hydraulic risks and face greater mortality risk. Moreover, in regions of more pronounced climatic change, we find evidence that forests are losing biomass, suggesting that species in these regions may be operating beyond their hydraulic limits. Continued climate change is likely to further reduce HSM 50 in the Amazon 6,7 , with strong implications for the Amazon carbon sink.
Publisher: Wiley
Date: 04-2022
DOI: 10.1002/AJB2.1827
Abstract: Evolutionary studies require solid phylogenetic frameworks, but increased volumes of phylogenomic data have revealed incongruent topologies among gene trees in many organisms both between and within genomes. Some of these incongruences indicate polytomies that may remain impossible to resolve. Here we investigate the degree of gene-tree discordance in Solanum, one of the largest flowering plant genera that includes the cultivated potato, tomato, and eggplant, as well as 24 minor crop plants. A densely s led species-level phylogeny of Solanum is built using unpublished and publicly available Sanger sequences comprising 60% of all accepted species (742 spp.) and nine regions (ITS, waxy, and seven plastid markers). The robustness of this topology is tested by examining a full plastome dataset with 140 species and a nuclear target-capture dataset with 39 species of Solanum (Angiosperms353 probe set). While the taxonomic framework of Solanum remained stable, gene tree conflicts and discordance between phylogenetic trees generated from the target-capture and plastome datasets were observed. The latter correspond to regions with short internodal branches, and network analysis and polytomy tests suggest the backbone is composed of three polytomies found at different evolutionary depths. The strongest area of discordance, near the crown node of Solanum, could potentially represent a hard polytomy. We argue that incomplete lineage sorting due to rapid ersification is the most likely cause for these polytomies, and that embracing the uncertainty that underlies them is crucial to understand the evolution of large and rapidly radiating lineages.
Publisher: Companhia Brasileira de Producao Cientifica
Date: 05-06-2020
DOI: 10.6008/CBPC2179-6858.2020.005.0043
Abstract: O presente artigo apresenta os resultados do Diagnóstico Participativo realizado com o objetivo de identificar as áreas de uso tradicional e os limites entre duas comunidades ribeirinhas na Floresta Nacional do Tapajós, visando compreender a dinâmica de uso e ocupação, pelas comunidades tradicionais, em uma Unidade de Conservação de uso sustentável na Amazônia brasileira. As áreas de uso tradicional, denominadas de Uso Familiar foram registradas por mapeamento participativo e levantamentos de c o. Os problemas ambientais foram identificados durante as entrevistas. O estudo mostrou que a comunidade do Jaguarari ocupa área de 6.271,01 hectares (ha) e Acaratinga ocupa 3.549,87 ha. Foram mapeadas 16 áreas de uso tradicional em Acaratinga e 22 no Jaguarari, que somam 111,44 e 243,08 ha, respectivamente. As áreas de uso intensivo correspondem a menos de 4% do território das comunidades pesquisadas e, de acordo com os comunitários, atende às necessidades a subsistência das famílias. Os principais usos do território estão relacionados com a agricultura, extrativismo madeireiro e não madeireiro, caça, pesca, turismo e pesquisa científica. Os problemas ambientais apontados pelos comunitários foram a caça e pesca predatórias, as queimadas, o furto de madeira e o desmatamento nas áreas de preservação permanente. Dentre as medidas indicadas para minimizar os problemas estão a fiscalização e c anhas de educação ambiental. O estudo indicou, a partir do olhar dos comunitários, que ocorreu a redução de animais e produtos florestais nos últimos cinco anos (2012-2017) e os fatores que afetaram os animais e produtos florestais foram as queimadas, a caça predatória, o desmatamento e o aumento da população. Recomenda-se ao órgão gestor buscar alternativas para o manejo adequado das áreas de uso familiar e investigar o real impacto desses fatores na bio ersidade local.
No related grants have been discovered for Leandro Giacomin.